//
//  UIImage+Extension.m
//  01-QQ聊天布局
//
//  Created by apple on 14-4-2.
//  Copyright (c) 2014年 itcast. All rights reserved.
//

#import "UIImage+Extension.h"

@implementation UIImage (Extension)
/**
 *  返回一张可以随意拉伸不变形的图片
 *
 *  @param name 图片
 */
+ (UIImage *)resizableImage:(UIImage *)normal
{
//    UIImage *normal = [UIImage imageNamed:name];
    CGFloat w = normal.size.width * 0.5;
    CGFloat h = normal.size.height * 0.5;
    return [normal resizableImageWithCapInsets:UIEdgeInsetsMake(h, w, h, w)];
}

// 生成缩略图
+ (UIImage *)thumbNailWithImageWithoutScale:(UIImage *)image size:(CGSize)asize
{
    
    UIImage *newimage;
    
    
    if (nil == image) {
        
        newimage = nil;
        
    }
    
    else{
        
        CGSize oldsize = image.size;
        
        CGRect rect;
        
        if (asize.width/asize.height > oldsize.width/oldsize.height) {
            
            rect.size.width = asize.height*oldsize.width/oldsize.height;
            
            rect.size.height = asize.height;
            
            rect.origin.x = (asize.width - rect.size.width)/2;
            
            rect.origin.y = 0;
            
        }
        
        else{
            
            rect.size.width = asize.width;
            
            rect.size.height = asize.width*oldsize.height/oldsize.width;
            
            rect.origin.x = 0;
            
            rect.origin.y = (asize.height - rect.size.height)/2;
            
        }
        
        
        UIGraphicsBeginImageContext(asize);
        
        CGContextRef context = UIGraphicsGetCurrentContext();
        
        CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);
        
        UIRectFill(CGRectMake(0, 0, asize.width, asize.height));//clear background
        
        [image drawInRect:rect];
        
        newimage = UIGraphicsGetImageFromCurrentImageContext();
        
        UIGraphicsEndImageContext();
        
    }
    
    
    return newimage;
    
}


static void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth,
                                 float ovalHeight)
{
    float fw, fh;
    
    if (ovalWidth == 0 || ovalHeight == 0)
    {
        CGContextAddRect(context, rect);
        return;
    }
    
    CGContextSaveGState(context);
    CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
    CGContextScaleCTM(context, ovalWidth, ovalHeight);
    fw = CGRectGetWidth(rect) / ovalWidth;
    fh = CGRectGetHeight(rect) / ovalHeight;
    
    CGContextMoveToPoint(context, fw, fh/2);  // Start at lower right corner
    CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);  // Top right corner
    CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner
    CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner
    CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right
    
    CGContextClosePath(context);
    CGContextRestoreGState(context);
}

+ (id)createRoundedRectImage:(UIImage*)image size:(CGSize)size radius:(NSInteger)r
{
    // the size of CGContextRef
    int w = size.width;
    int h = size.height;
    
    UIImage *img = image;
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
    CGRect rect = CGRectMake(0, 0, w, h);
    
    CGContextBeginPath(context);
    addRoundedRectToPath(context, rect, r, r);
    CGContextClosePath(context);
    CGContextClip(context);
    CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);
    CGImageRef imageMasked = CGBitmapContextCreateImage(context);
    img = [UIImage imageWithCGImage:imageMasked];
    
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(imageMasked);
    
    return img;
}

+ (UIImage *)imageWithUIView:(UIView *)view
{
    
    // 创建一个bitmap的context
    // 并把它设置成为当前正在使用的context
    UIGraphicsBeginImageContext(view.bounds.size);
    CGContextRef currnetContext = UIGraphicsGetCurrentContext();
    [view.layer renderInContext:currnetContext];
    // 从当前context中创建一个改变大小后的图片
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    // 使当前的context出堆栈
    UIGraphicsEndImageContext();
    return image;
}



@end
